C-1
From PigBoats.COM
Octopus on the building ways at Fore River Shipbuilding Co., Quincy, MA., probably just before her launch on October 4, 1906. Electric Boat's patented rotating bow cap for the muzzle doors of the torpedo tubes can clearly be seen here. The C-class had just two tubes. To open the muzzle ends of the tubes, the crew would manipulate controls inside the torpedo room that pushed the cap slightly forward to unseat the rubber gasket around each tube. A large handwheel inside the torpedo room would then be turned to rotate the cap so that the cutouts lined up with the tube muzzle ends. Once the tubes were shot, the crew would perform the opposite procedure: rotate the cap so that the cutouts in the cap were behind the upper and lower superstructure, then pull the lever back that seated the cap, creating a watertight seal on the muzzle end of the tube. EB would use the rotating cap feature on nearly all of its submarines up to the O-class of 1918. The two exceptions were the L and M-class. On the lower right on the bottom of the boat the port side bilge keel can be seen. This feature help to reduce rolling while on the surface.